Thankyou so much for your reply. So it is badged corsa on the top tube, but has the zinc corrosion proof etc sticker which only later frames have? Has the curved rear dropout branded merckx and the short tube behind the bb shell between the two stays looks like 3 athlete. It's metallic grey by the way, exact same as some other frames on your thread. A re sprayed 3 athlete? It has no tubing sticker. It's a 60cm frame so that's the 0 and A must be the worker code letter? Can't believe it's 501?! Doesn't feel heavy and pretty sure has a 27 or 27.2 seat post.